The present invention relates to database management systems, and more specifically, to recovery of data in Relational Database Management System to a point in time before the object's schema definition was changed or modified. A relational database can be generally described as a collection of data items organized as a set of formally described tables from which data can be accessed easily. The software used in a relational database is typically referred to as a Relational Database Management System (RDBMS). One example of an RDBMS is the DB2, which is available from International Business Machines Corporation of Armonk, N.Y.
In some RDBMSs, such as the DB2, there is the concept of pending schema definition changes. Pending schema definition changes are only materialized and applied to both the metadata and data when a subsequent process that reorganizes the object's data is executed. One example of pending definition changes is ALTER statements relating to changes of various properties of table spaces (e.g., segment size, data set size, buffer pool page size, table space type, etc.).
Recovery to a point in time (PIT) prior to pending definition changes were materialized is not permitted in a RDBMS. There needs to be a way to allow such recovery on the data, because this restriction could otherwise cause the loss of data or the loss of availability to the data in a customer production environment. This includes, for example, scenarios when immediate ALTER statements were issued during a window between the subsequent processing which materialized pending definition changes and the point-in-time recovery processing.